I am late replying to your post and wonder if you ever made it to Kentucky. I live here in Lexington and we have beautiful scenic parks.
I too have the 454 and mine only has 2000 miles on it but I am wondering if the quad needs rebuilt due to fuel draining after a few days making for hard starts. I too am considering and most likely will do a EFI TBI conversion. I did this on a 460 ford in my last Fleetwood and was impressed with the power results but, I also did a full Banks conversion which was big headers and more.
What I think every post on here failed to mention about the benefits of TBI EFI is how much fuel injection improves the life of the engine. The single biggest improvement to modern engines now easily going 200-300 thousand miles or more is the precision metering of air fuel due to modern fuel injection. We have done extensive studies and experimental testing on EFI in aircraft and air racing engines which are commonly automotive conversion engine in air racing. Briefly, when an engine gets to rich a mixture it washes the cylinder walls in fuel. This leads to premature oil contamination and piton ring wear. In a lean burn situation this can lead to much higher engine temps and can result in burned valves and other high temp wear and failure.
I stopped by the shop to discuss my idea of doing a TBI EFI conversion and the top mechanic had a fit. Telling me my Quad was the perfect carb and if the carb was not right they would rebuild it because nothing could out perform a properly rebuilt Quad. All respect due, he is so wrong. Anyone here who thinks a TBI EFI is not worth the cost and effort to do is not weighing all the facts. A carb, no carb can keep a proper AF ratio at changing altitudes, speeds, load and other varying conditions and therefore can not allow your engine to be its most efficient be as dependable to start and give the endurance that a TBI or full EFI system. At a proper A/F your engine will produce its maximum power at all conditions. Therefore you will use less fuel and put less stress on the engine. Although I am weighing the balance between going TBI EFI or overdirve/ 700R4 transmission. Which I do first or last or is a matter of which I feel will leave my Argosy 28 down the shortest amount of time and which one I will get the best return on. I also need to look at the long term cost benefit. Will I really drive the Argosy long enough to justify the EFI and therefore get the added engine life out of ? Will the 20 to 30% reduction in engine RPMs at cruise have a better effect on Fuel econ from lower RPM and therefore lower wear and tear on the engine and get my engine into what Terry knowingly refers to as my engines RPM sweet spot of efficiency ? At about a third the cost of the EFI conversion ? One big factor is, I will be doing all the work myself so I don't have the shop cost. Bottom line is, there is a reason why modern engines use EFI. You can argue the benefits. Better fuel econ, easier starts and dependability, longer engine life and far longer times between tune ups and oil changes. Add those indirect costs into your calculations for your return and its easy to see the answers.